Arnab Karmakar has posted comments on this change. ( http://gerrit.cloudera.org:8080/23566 )
Change subject: IMPALA-14065: Support WHERE clause in SHOW PARTITIONS statement ...................................................................... Patch Set 14: (2 comments) http://gerrit.cloudera.org:8080/#/c/23566/13/fe/src/main/java/org/apache/impala/analysis/ShowStatsStmt.java File fe/src/main/java/org/apache/impala/analysis/ShowStatsStmt.java: http://gerrit.cloudera.org:8080/#/c/23566/13/fe/src/main/java/org/apache/impala/analysis/ShowStatsStmt.java@225 PS13, Line 225: "Aggregate functions are not allowed in SHOW PARTITIONS WHERE"); > nit: why does this say "SHOW PARTITIONS WHERE clause" but the two preceding Nice find, Done http://gerrit.cloudera.org:8080/#/c/23566/13/tests/metadata/test_metadata_query_statements.py File tests/metadata/test_metadata_query_statements.py: http://gerrit.cloudera.org:8080/#/c/23566/13/tests/metadata/test_metadata_query_statements.py@79 PS13, Line 79: assert len(result.data) > 0, "SHOW PARTITIONS with rand() should return some \ > There's a non-zero chance that all invocations of rand() return >= 0.5. The Well, the way rand() works here is different from SELECT WHERE. SHOW PARTITIONS doesn't involve backend evaluation and we're not using the pcg32 here(stateful generator), thereby even though this function is evaluated for each partition, rand() will always return 0.47. When HdfsPartitionFilter.getMatchingPartitionIds() is used to filter partitions, we lose the state and all calls to FeSupport.EvalPredicateBatch() for evaluating rand() return the same result. i.e. 0.47. This behaviour of rand() is documented and I've talked about this with Quanlong, and we have other ways of getting random partitions like using uuid(). -- To view, visit http://gerrit.cloudera.org:8080/23566 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I2e2a14aabcea3fb17083d4ad6f87b7861113f89e Gerrit-Change-Number: 23566 Gerrit-PatchSet: 14 Gerrit-Owner: Arnab Karmakar <[email protected]> Gerrit-Reviewer: Arnab Karmakar <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Peter Rozsa <[email protected]> Gerrit-Reviewer: Pranav Lodha <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Riza Suminto <[email protected]> Gerrit-Reviewer: Surya Hebbar <[email protected]> Gerrit-Comment-Date: Wed, 10 Dec 2025 04:33:41 +0000 Gerrit-HasComments: Yes
